Guitar-heavy American rock music of the 1970s. The phrase originated in 1987: "Freedom Rock" was the title of a sold-only-on-TV music compilation. The memorably cheezy commercial featured two aging Cheech and Chong-type hippies sitting at the back of their Tour van; as I recall it, Hippy #1 hears what Hippy #2 is playing on his radio and asks, "Hey, man, is that freedom rock?" Hippy #2, says, "Yeah, man!" and Hippy #1 enthusiastically replies, "Well, turn it up, man!"